namespace Filters.Infrastructure
{
  public interface IFilterDiagnostics
  {
    IEnumerable<string> Messages { get; }
    void AddMessage(string message);
  }
  public class DefaultFilterDiagnostics:IFilterDiagnostics
  {
    private List<string> messages = new List<string>();
    public IEnumerable<string> Messages => messages;
    public void AddMessage(string message) => messages.Add(message);
  }
}
